1. Technical Field
The present invention relates to an organic electroluminescence device and a method for producing the organic electroluminescence device.
2. Related Art
In recent years, the need for flat display devices having reduced power consumption and a reduced weight has been growing with diversification of information technology devices, for example. As one of such flat display devices, an organic electroluminescence (hereinafter referred to as “organic EL”) device has been proposed in which display is performed by making an organic EL element having an organic function layer, such as a light emitting layer or a hole transporting layer emit light.
The organic EL element deteriorates, brightness decreases, and emission life becomes short due to contact with moisture or oxygen in the air. Therefore, as a structure of the organic EL device, a structure is employed in which the organic EL element is disposed between a pair of substrates facing each other, and the peripheries of the substrates are adhered with an adhesive, so that moisture or oxygen is prevented from entering the inside of the organic EL device. In a process of bonding the substrates, which is one of the processes of producing the organic EL device, a pair of substrates are bonded to each other in a nitrogen atmosphere. Therefore, in the inside of the organic EL device, the organic EL element is disposed in a nitrogen atmosphere from which moisture or oxygen has been removed.
As a structure in which the organic EL element is sealed in the organic EL device, a structure is generally known in which the peripheries of the pair of substrates are sealed using a resin adhesive. In recent years, a sealing structure has been proposed in which the outer periphery of the organic EL element is completely sealed using a glass paste in which powdery glass frit has been mixed with a resin paste (e.g., JP-A-2001-319775).
However, a glass material is easily broken when a stress is applied. More specifically, a glass material has a disadvantage that resistance against an external stress is low. Therefore, the sealing structure disclosed in JP-A-2001-319775 has a problem that, in the case where a driver circuit or the like is mounted on a substrate or when a substrate is transported, for example, when an external stress is applied to the substrate, the substrate bends, causing cracks or separation in the glass sealing structure.